Inadvertent MRI in a patient with an active ICD caused electromagnetic noise detected as ventricular fibrillation, prolonged charge time, and an increased pacing threshold to 2.8 V at 3 months.
Case Report (n=1)
Does MRI cause device dysfunction in patients with an active implantable cardioverter defibrillator?
MRI in patients with an active ICD can cause severe device dysfunction, including inappropriate shock triggers and altered pacing thresholds, reinforcing that it remains contraindicated.
This report describes a patient in whom a MRI of the brain was performed without realizing that an ICD had been implanted 8 days previously. Electromagnetic noise induced during the MRI was detected as ventricular fibrillation and nearly caused inappropriate shocks. Charge time during MRI was prolonged. The battery indicator switched to "end of life," but this was reversed by capacitor reformation. These problems could have been avoided by inactivating the ICD prior to MRI. Three months later, the pacing threshold increased from 0.4 V per 0.5 ms at implantation to 2.8 V per 0.5. It is still uncertain whether radiofrequency current heating at the electrode tip caused the increased pacing threshold or if this would have occurred independently of the MRI. MRI of patients with an active ICD may cause life-threatening complications, and it is unknown if MRI may be safely performed if the ICD is inactivated. Therefore, MRI of patients with an ICD remains contraindicated.
Anfinsen et al. (2002) conducted a case report in Implantable Cardioverter Defibrillator (ICD) (n=1). Magnetic Resonance Imaging (MRI) was evaluated on ICD dysfunction and complications. Inadvertent MRI in a patient with an active ICD caused electromagnetic noise detected as ventricular fibrillation, prolonged charge time, and an increased pacing threshold to 2.8 V at 3 months.